For effective hand hygiene, water temperature matters less than time, new research states. The finding runs counter to U.S. Food and Drug Administration guidelines recommending that food establishments and restaurants deliver water at 100 degrees Fahrenheit for hand washing, the researchers said. Scientists at Rutgers University in New Jersey said they found that cold water is as effective as hot in getting rid of harmful bacteria and other germs. What's more important, they said, is that people scrub their hands with soap for at least 10 seconds.

For the study, the researchers contaminated the hands of 21 volunteers with high levels of a harmless bacteria several times over six months. The participants were then asked to wash their hands in 60-degree, 79-degree or 100-degree water.

The amount of soap the people used didn't affect the findings. The researchers noted that more study is needed to determine exactly how much soap and what types are best for removing potentially harmful germs. Referring to the FDA guidelines for the food service industry, the findings suggest a policy change is in order.

Instead of having a temperature requirement, the policy should only say that comfortable or warm water needs to be delivered - energy to heat water to a level that is not necessary is therefore being wasted." The study appears in the June issue of the Journal of Food Protection.